package com.zxlfysj.tree;

/**
 * 二叉树
 *
 * @author yangshujing
 * @create 2020-08-19 16:32
 */
public class BinaryTreeDemo {
    public static void main(String[] args) {
        //创建二叉树
        BinaryTree binaryTree = new BinaryTree();
        HeroNode root = new HeroNode(1, "李白");
        HeroNode node2 = new HeroNode(2, "项羽");
        HeroNode node3 = new HeroNode(3, "曹操");
        HeroNode node4 = new HeroNode(4, "貂蝉");
        HeroNode node5 = new HeroNode(5, "王昭君");
        root.setLeft(node2);
        root.setRight(node3);
        node3.setRight(node4);
        node2.setRight(node5);
        binaryTree.setRoot(root);
        //测试前序遍历
        binaryTree.preOrder();
        System.out.println("***********");
        //测试中序遍历
        binaryTree.infixOrder();
        System.out.println("**********");
        //测试后序遍历
        binaryTree.postOrder();
        //测试前序查找
        binaryTree.preOrderSearch(5);
        //测试中序查找
        binaryTree.infixOrderSearch(5);
        //测试后序查找
        binaryTree.postOrderSearch(5);

        //测试删除节点
        binaryTree.delNode(3);
        System.out.println("删除节点后");
        binaryTree.postOrder();


    }
}

//定义二叉树
class BinaryTree {
    private HeroNode root;

    public void setRoot(HeroNode root) {
        this.root = root;
    }

    //删除节点
    public void delNode(int no) {
        if(root != null) {
            if(root.getNo() == no) {
                root = null;
                return;
            } else {
                root.delNode(no);
            }
        } else{
            System.out.println("这是颗空树");
            return;
        }
    }

    //前序遍历
    public void preOrder() {
        if (this.root != null) {
            this.root.preOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //中序遍历
    public void infixOrder() {
        if (this.root != null) {
            this.root.infixOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //后序遍历
    public void postOrder() {
        if (this.root != null) {
            this.root.postOrder();
        } else {
            System.out.println("二叉树为空");
        }
    }

    //前序遍历查找
    public HeroNode preOrderSearch(int no) {
        if (this.root != null) {
            return this.root.preOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }

    //中序遍历查找
    public HeroNode infixOrderSearch(int no) {
        if (this.root != null) {
            return this.root.infixOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }

    //后序遍历查找
    public HeroNode postOrderSearch(int no) {
        if (this.root != null) {
            return this.root.postOrderSearch(no);
        } else {
            System.out.println("二叉树为空");
            return null;
        }
    }
}

class HeroNode {
    private int no;
    private String name;
    private HeroNode left;
    private HeroNode right;

    public HeroNode(int no, String name) {
        this.no = no;
        this.name = name;
    }

    public int getNo() {
        return no;
    }

    public void setNo(int no) {
        this.no = no;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public HeroNode getLeft() {
        return left;
    }

    public void setLeft(HeroNode left) {
        this.left = left;
    }

    public HeroNode getRight() {
        return right;
    }

    public void setRight(HeroNode right) {
        this.right = right;
    }

    @Override
    public String toString() {
        return "HeroNode{" +
                "no=" + no +
                ", name='" + name + '\'' +
                '}';
    }

    //递归删除结点
    //1、如果删除的是叶子结点，则删除此节点
    //2、如果删除的是非叶子结点，则删除该子树
    public void delNode(int no) {
        if( this.left != null &&this.left.no == no) {
            this.left = null;
            return;
        }
        if( this.right != null &&this.right.no == no) {
            this.right = null;
            return;
        }
        //向左子树递归删除
        if(this.left != null) {
            this.left.delNode(no);
        }
        //向右子树递归删除
        if(this.right != null) {
            this.right.delNode(no);
        }

    }

    //前序遍历
    public void preOrder() {
        System.out.println(this); //输出父节点
        //向左子树递归前序遍历
        if (this.left != null) {
            this.left.preOrder();
        }
        //向右子树递归前序遍历
        if (this.right != null) {
            this.right.preOrder();
        }
    }

    //中序遍历
    public void infixOrder() {
        //向左子树递归中序遍历
        if (this.left != null) {
            this.left.infixOrder();
        }
        //输出父节点
        System.out.println(this);
        //向右子树递归中序遍历
        if (this.right != null) {
            this.right.infixOrder();
        }

    }

    //后序遍历
    public void postOrder() {
        //向左子树递归后序遍历
        if (this.left != null) {
            this.left.postOrder();
        }
        //向右子树递归后序遍历
        if (this.right != null) {
            this.right.postOrder();
        }
        //输出父节点
        System.out.println(this);
    }

    //前序遍历查找
    public HeroNode preOrderSearch(int no) {
        //比较父节点
        if (this.no == no) {
            return this;
        }
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.preOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.preOrderSearch(no);
        }
        return resNode;

    }

    //中序遍历查找
    public HeroNode infixOrderSearch(int no) {
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.infixOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //比较父节点
        if (this.no == no) {
            resNode = this;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.infixOrderSearch(no);
        }
        return resNode;

    }

    //后序遍历查找
    public HeroNode postOrderSearch(int no) {
        HeroNode resNode = null;
        //向左子树递归查找
        if (this.left != null) {
            resNode = this.left.postOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //向右子树递归查找
        if (this.right != null) {
            resNode = this.right.postOrderSearch(no);
        }
        if (resNode != null) {
            return resNode;
        }
        //比较父节点
        if (this.no == no) {
            resNode = this;
        }
        return resNode;
    }
}
